Dynamic Light Scattering of DNA-Ligand Complexes

Dynamic light scattering (DLS) enables the characterization of sizes and electrokinetic properties of colloids, polymers, and macromolecules. DNA is a charged semiflexible polyelectrolyte that is condensed or compacted by counterions, proteins, and other condensing agents in processes such as chromosome compaction and gene therapeutic applications. DNA condensation is closely related to charge screening since packaging requires effective neutralization of its surface negative charges. In this chapter, we describe in detail the protocol for DLS DNA-ligand complexes. As an example, we describe data for the condensation of DNA by chitosan and the measurement of size, zeta potential, and electrophoretic mobility of the DNA-ligand complex by DLS.